50 Million Americans Prepare For "Potentially Historic" Winter Storm

With the exception of a handful of one-time events, it had been such a mild winter across most of the U.S. that numerous retailers have been complaining how negatively impacted their topline has been as a result of the warmer weather (clearly having forgotten how they complained about precisely the opposite in prior years).

All that is about to change, and all those warm weather-slammed retailers are about to get just the top line-boosting gift they have been waiting for because according to AccuWeather, the Northeast - from Charleston all the way to Boston - is about to be hit with a major winter storm, with the potential for heavy snow to impact more than 50 million people at the end of the week.

AccuWeather Senior Meteorologist Dave Dombek says that "we are just now at the point [of the winter] where the air is cold enough with the ongoing storms to awaken a sleeping giant in terms of a snowstorm."

He adds that unlike most storms so far this winter, this system will have enough cold air to produce snow and disruptions to daily activities in areas of the East that have received little thus far.

The exact track of the storm will hold the key as to which areas in the mid-Atlantic and southern New England are hit with heavy snow, dangerous highway travel and scores of flight delays and cancellations during Friday into Saturday.

The heavy snow with the storm is likely to have a fairly sharp northern edge. At this time, the northern edge of the storm is most likely to extend from southern Ohio to southern New England. A distance of less than 50 miles could bring snowfall ranging from an inch or less to more than a foot.

There is a chance the major storm will not evolve into a full-blown blizzard: if the storm develops to its full potential and takes a track just off the mid-Atlantic and New England coasts, then a blizzard can unfold. The storm could shut down highways and perhaps cause airport closures.

According to AccuWeather Chief Meteorologist Elliot Abrams, "This could be a long-duration snowfall that could last more than 24 hours in some locations." This is also the type of storm that is likely to produce a very heavy rate of snow.

Based on the most likely storm track at this early stage, areas from the Virginia and West Virginia mountains to the major cities from Washington, D.C., to Baltimore and Philadelphia, as well as the suburbs, are included in the swath of heavy snow potential.

AccuWeather warns residents in the region that since the storm will strengthen rapidly, reduce its forward speed and tap plenty of moisture from the Gulf of Mexico and the Atlantic Ocean on its path, snowfall rates of 1-3 inches per hour are possible. There is the potential for the hardest-hit areas to receive 1-2 feet of snow or more from the storm, where rain does not mix in.

According to AccuWeather Senior Meteorologist Brett Anderson, "Should the storm continue northeastward, rather than turn more to the east at the last minute, New York City, Boston, Providence, Rhode Island, and Hartford, Connecticut, would also be buried in snow."

A wintry mix is likely to occur from northwestern North Carolina to the Delmarva Peninsula, southern New Jersey and Long Island. Exactly how much snow accumulates in the coastal areas will depend on the amount of rain, if any, that mixes in.

In the swath of the heaviest snow, motorists who venture out during the storm could become stranded.

Thunder and lightning could accompany the heavy snow in some coastal locations. As the storm strengthens near the coast, winds will increase, and blowing and drifting of snow will occur.

But while AccuWeather is still on the fences about the storm's ultimate impact, the WaPo's DC-based meteorologists are far less sanguine and are confident that the storm's impact is now assured: as it reported, "a high-impact snowstorm for the region is nearing inevitability and there is some chance it will be historic, paralyzing travel and disrupting normal routines."

They add that "every major computer model is now forecasting double-digit snowfall totals for the D.C. area Friday and Saturday."

If the WaPo is accurate, the storm will be truly 'historic': "The agreement among forecast models for a severe winter storm in this case is remarkable and a hallmark of some of our most memorable snow events." However, even the WaPo hedges somewhat and notes that "this storm is still three days from starting, which means there is time for shifts."

Meanwhile, the National Weather Service has raised its winter-storm-threat scale to its highest level. It warns there is potential for significant travel delays, closures, and threats to life and property, and is urging residents to start planning ahead.

In addition to heavy snow, the combination of wet snow and high winds are possible Friday night through Saturday, which could lead to power outages.

How much snow should the up to 50 million residents in the impacted region anticipate?

The snow is forecast to begin between Friday morning and afternoon. The heaviest snowfall and most difficult conditions are likely to start late Friday afternoon into Saturday.

Exactly how much snow falls and where is sensitive to the exact storm track, which will invariably jump around a bit. As areas along and east of Interstate 95 will be close to the snow-sleet-rain line, these shifts could well have profound implications on specific amounts and the overall storm impact.

There is still a small chance the storm tracks far enough to the southeast that this is more of a moderate snowstorm rather than a blockbuster. As such, we are not yet in position to forecast specific snow amounts, but rather provide percent likelihoods of different totals.

For the D.C. metro-area, the WaPo gives the following prediction:

Chance of at least 1 inch: 90 percent

Chance of at least 4 inches: 75 percent

Chance of at least 8 inches: 65 percent

Chance of at least 12 inches: 50 percent

Chance of at least 20 inches: 15 percent

The answer will be revealed on Friday, and if the worst case scenarios are accurate it will present retailers with a major quandary, because if after blaming Q4 sales on warm weather, should the top line not recur in the first quarter after what could be a "historic" snow storm, then the contradictory explanations will get more problematic.

And then there is the US economy in general: recall that in 2014 and 2015 it was the harsh winter weather that was blamed for the dramatic drop in Q1 GDP of both years. Well, with Q4 GDP already tracking at 0.6% according to the Atlanta Fed, and 0.1% according to JPM - and could potentially be negative - it will be the height of scapegoating irony if GDP declines from a zero, or negative, print and one strong winter storm is the factor that pushes the US into a technical recession.

At least the NBER will have a convenient climatic "alibi" on which to blame the "first recession" in 7 years.